Friction modifier for oil-based (invert) well drilling fluids and methods of using the same

ABSTRACT

This invention relates to a composition comprising a water-in-oil emulsion formed from a brine, a liquid oil, (A) an emulsifier, (B) a friction modifier of the following formula: ##STR1## where X=1 to 4, z=1 to 6, 
     Q=0 to 2 
     R 1  and R 2  are independently H or an aliphatic group containing from 1 to about 16 carbon atoms, provided that the sum of R 1  and R 2  is between 0 and about 16, 
     R&#39; is an aliphatic group containing an average of from about 8 to about 24 carbon atoms, and 
     R&#34; is selected from the group consisting of H, an aliphatic group containing between 1 and an average of about 18 carbons, and ##STR2## where Q, X, z, R 1 , R 2 , R&#39; and R&#34; are defined as set forth above, and Y is 0 to 5. In a preferred embodiment, z is 1. In the most preferred embodiment, Q=0, R 1  and R 2  are both H, X, and z all equal 1, R&#39; is n-dodecyl, and R&#34; is H. The compositions of the present invention have beneficial lubrication properties. These compositions are useful in drilling, working and completing well bore holes.

TECHNICAL FIELD

This invention relates to friction modifier useful in drilling fluidcompositions which serves to decrease the coefficient of friction of thewell drilling fluid. The lowering of the coefficient of friction lowersthe force required to turn the drill bit in the hole. Gravitationalforces increase the coefficient of friction in deviated, horizontal andextended reach wells. It is this type of application where thisinvention becomes most useful.

BACKGROUND OF THE INVENTION

The primary functions of a drilling fluid or mud are: to carry chips andcuttings produced by drilling to the surface; to lubricate and cool thedrill bit and drill string; to form a filter cake which obstructsfiltrate invasion in the formation; to maintain the walls of theborehole; to control formation pressures and prevent lost returns; tosuspend cuttings during rig shutdowns; and to protect the formation forlater successful completion and production. Friction between thedrilling apparatus and the borehole is a problem. The greater thefriction, the higher the energy required for the drilling process. Thehigher the friction, the more likely other problems such as drill bitsticking are to occur. In addition, in non-vertically, e.g.horizontally, drilled wells, a reduction in the coefficient of frictionmakes the non-vertical drilling operation easier. Accordingly it isdesirable to use a friction modifying agent which decreases the frictionof the drilling process and thereby decreases the probability of bitsticking, decreases the energy costs of drilling, and facilitatesnon-vertical drilling. It is an object of this invention to supply sucha friction modifying agent.

Useful drilling fluids or muds must maintain rheological and viscosityproperties under normal operation conditions. Also, the drilling fluidsor muds must be able to suspend cuttings and weighting materials uponstopping of circulation of the drilling fluid. It is desirable to havedrilling fluids or muds which maintain thixotropy and rheology even withincreased solids. Weighting agents and organophilic clays may be used toprovide higher viscosity and density to the muds.

There are two major types of drilling fluids, or muds, in use today. Inaddition, a somewhat different foam drilling fluid is occasionally used.The fluids are either oil based or water based. The oil based fluids aregenerally water-in-oil emulsions which contain some water in the form ofa discontinuous emulsified phase. The oil is the continuous phase. Theother major type of drilling fluids are the water based drilling fluidsThese water based compositions may contain some oil phase. If oil ispresent, it exists as a discontinuous emulsified phase. Accordingly, thewater based fluids which contain oil, are oil-in-water emulsions. Sincethe external properties of emulsions, such as dispersability, wettingcharacteristics, and feel, are determined by the continuous phase, theoil based fluids are more like oil, even though they contain water, andthe water based fluids are more like water, even though they may containoil.

The drilling muds of the present invention are water-in-oil emulsions.The optional weighting agents and organophilic clays are generally inthe oil phase of the muds. If these materials become water wet (e.g.present in the brine phase of the emulsion), then the emulsion isweakened. If the emulsion is weakened sufficiently, the emulsion mayflip, e.g. go from an water-in-oil (e.g. invert) emulsion to aoil-in-water (regular) emulsion. When the emulsion flips, it renders itunusable in well-drilling applications.

U.S. Pat. No. 3,236,769 discloses drilling fluids containing water andclay to which is added a defoamant and a water-soluble, non-ioniccompound having surface active properties and characterized by theformula: R-(x-[(CH2-CH2-0)n-H]m)y. The non-ionic compound functions as aflocculating or agglomerating agent for clay.

U.S. Pat. No. 4,031,023 discloses lubricating compositions havingoxidative stability and anti-wear properties contributed by certainhydroxy thioethers. These thioethers include molecules such as 2-hydroxyethyl n-decyl sulfide.

U.S. Pat. No. 4,172,800 discloses aqueous drilling fluids containing anadmixture of a polyethoxylated sulfurized fatty acid and polyalkyleneglycol. Such fluids are especially useful where reduced torque drillingfluids are needed.

U.S. Pat. No. 4,181,617 discloses an aqueous drilling fluid having alubricant consisting essentially of the reaction product of a fattyvegetable oil with 4,4'-thiodiphenol.

SUMMARY OF THE INVENTION

This invention relates to a composition comprising a water-in-oilemulsion formed from a brine, a liquid oil, (A) an emulsifier, (B) afriction modifier of the following formula: ##STR3## where X=1 to 4, z=1to 6,

Q=0 to 2

R₁ and R₂ are independently H or an aliphatic group containing from 1 toabout 16 carbon atoms, provided that the sum of R₁ and R₂ is between 0and about 16,

R' is an aliphatic group containing an average of from about 8 to about24 carbon atoms, and

R" is selected from the group consisting of H, an aliphatic groupcontaining between 1 and an average of about 18 carbons, and ##STR4##where Q, X, z, R₁, R₂, R' and R" are defined as set forth above, and Yis 0 to 5. In a preferred embodiment, z is 1. In the most preferredembodiment, Q=0, R₁ and R₂ are both H, X, and z all equal 1, R' isn-dodecyl, and R" is H.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The term "emulsion" as used in the specification and the claims isintended to cover water-in-oil emulsions. The term is also intended tocover compositions derived from or formulated as water-in-oil emulsionswhich are gelatinous or semi-gelatinous compositions.

The term "hydrocarbyl" includes hydrocarbon, as well as substantiallyhydrocarbon, groups. Substantially hydrocarbon describes groups whichcontain non-hydrocarbon substituents which do not alter thepredominantly hydrocarbon nature of the group.

Examples of hydrocarbyl groups include the following:

(1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl oralkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents,aromatic-substituted aliphatic substituents or aromatic-substitutedalicyclic substituents, or aliphatic- and alicyclic-substituted aromaticsubstituents and the like as well as cyclic substituents wherein thering is completed through another portion of the molecule (that is, forexample, any two indicated substituents may together form an alicyclicradical);

(2) substituted hydrocarbon substituents, that is, those substituentscontaining non-hydrocarbon groups which, in the context of thisinvention, do not alter the predominantly hydrocarbon nature of thesubstituent; those skilled in the art will be aware of such groups(e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto,alkylthio, nitro, nitroso, sulfoxy, etc.);

(3) hereto substituents, that is, substituents which will, while havinga predominantly hydrocarbon character within the context of thisinvention, contain an atom other than carbon present in a ring or chainotherwise composed of carbon atoms. Suitable heteroatoms will beapparent to those of ordinary skill in the an and include, for example,sulfur, oxygen, nitrogen and such substituents as, e.g., pyridyl, furyl,thienyl, imidazolyl, etc. In general, no more than about 2, preferablyno more than one, non-hydrocarbon substituent will be present for everyten carbon atoms in the hydrocarbyl group. Typically, there will be nosuch non-hydrocarbon substituents in the hydrocarbyl group. Thehydrocarbyl group may be purely hydrocarbon.

As used in the specification and claims a "barrel" is 42 gallons U.S.

As described above, the present invention relates to a compositioncomprising a water-in-oil emulsion formed from a brine, a liquid oil,(A) an emulsifier, (B) a friction modifier of the following formula:##STR5## where X=1 to 4, z=1 to 6,

Q=0 to 2

R₁ and R₂ are independently H or an aliphatic group containing from 1 toabout 16 carbon atoms, provided that the sum of R₁ and R₂ is between 0and about 16,

R' is an aliphatic group containing an average of from about 8 to about24 carbon atoms, and

R" is selected from the group consisting of H, an aliphatic groupcontaining between 1 and an average of about 18 carbons, and ##STR6##where Q, X, z, R₁, R₂, R' and R" are defined as set forth above, and Yis 0 to 5. In a preferred embodiment, z is 1. In the most preferredembodiment, Q=0, R₁ and R₂ are both H, X, and z all equal 1, R' isn-dodecyl, and R" is H.

The friction modifiers may be prepared by condensation reactions. Forexample, n-dodecyl-(2-hydroxyethyl) sulfide may be prepared bycondensing 1-dodecene with mercaptoethanol. The corresponding bis ether,2,2'- di-(n-dodecylthio)-diethyl ether may be prepared by condensing thealcohol in the presence of an acid catalyst. The R" group may be ahydrogen, in which case the molecule is an ether. R" may also be analiphatic group containing between 1 to an average of about 18 carbonatoms. If R" is an aliphatic group, the molecules may be prepared bycondensing a mixture of the thio-ether alcohol with the desiredaliphatic alcohol. Such a synthesis will likely result in the formationof some di-aliphatic ether which would probably not present a problem indrilling mud applications. R" may be a thio-ether radical as shown inthe structure above. Different thio-ether radicals may be coupled tocreate unsymetrical ethers. Finally, R" may be a mixture of thio-etherradicals, aliphatic radicals, and hydrogen. Such ethers, and mixtures ofethers may be prepared by the condensation of appropriate combinationsof alcohols. If it is desired to prepare a mixture in which some of theR" are hydrogen and others are thio-ether radicals or aliphaticradicals, this may be accomplished by conducting the condensationreaction so that it does not go completion, and accordingly, someunreacted thioether alcohol remains.

The ##STR7## groups may be prepared by reaction of an epoxide with asuitable mercaptan. The reaction may be conducted in the presence ofsulfur if the desired product is a polysulfide species (X=2 to 4 in theformula above). The epoxide may be a terminal epoxide or it may be anepoxide formed from a non-terminal olefin. The preferred epoxides areethylene and propylene oxide. These reactions are carried out in thepresence of an alkaline catalyst such as sodium or potassium methoxideat temperatures from 100-200C. With the lower epoxides such as ethyleneoxide, the reactions are run under pressure. The resulting structureswith a terminal hydroxyl group can be further condensed with itself orwith other aliphatic alcohols to form the subsequent ether structures.These reactions are run with strong acid catalysts such as sulfuric acidor methane sulfonic acid at temperatures from 100-200C. The water formedduring the reaction is removed under these conditions. Some of themolecules may also be prepared by the reaction of alpha olefins withthioglycols. These reactions are generally run in the presence of freeradical catalysts at temperatures from 75-100C.

EMULSIFIERS

The friction modifier of the present invention operates in water-in-oilemulsion drilling fluids or muds. Any emulsifier suitable as awater-in-oil emulsifiers may be used in preparing the drilling fluids.These emulsifiers preferably have HLB's (hydrophile-lipophile balance)of less than 10 and more preferably in the range of 4 to 8. Suchemulsifiers are well known in the art and lists as well as methods ofpreparing the emulsions are given in sources such as the Kirk Othmer's"Encyclopedia of Chemical Technology", 3rd Edition, Vol. 8, pages900-930, Interscience Publishers, New York (1979). Often similar typesof chemical emulsifiers are used to prepare water-in-oil andoil-in-water emulsions. However, within any given chemical type, it isimportant to select emulsifiers having the proper HLB for thepreparation of water-in-oil emulsion. The following are examples ofuseful emulsifiers:

AMINE DERIVATIVE OF CARBOXYLIC ACYLATING AGENTS

The reaction products of carboxylic acylating agents withpolyalkylenepolyamines and hydroxylamines are especially usefulemulsifiers. The carboxylic acylating agents include mono, di, tri andsuccinic acylating agents.

CARBOXYLIC ACYLATING AGENTS

The carboxylic acylating agents are carboxylic acylating agents havingfrom about 1 to about 4 carboxylic groups, preferably 2 or 3. The termacylating agents encompasses acids, arthydrides, lower esters (C₁₋₇esters), halides, etc. Preferably, the acylating agents are acids oranhydrides. Carboxylic acylating agents may be monocarboxylic orpolycarboxylic acylating agents.

Monocarboxylic acylating agents include fatty carboxylic acylatingagents including fatty acids and Dieis-Alder monocarboxylic reactionproducts. Fatty acids generally contain from about 8, preferably fromabout 10, more preferably from about 12 to about 30, more preferably toabout 24 carbon atoms. Examples of fatty acids include stearic, oleic,lauric, linoleic, abietic, palmitic, sebacic, linolenic, behenic, talloil and rosin acids.

The polycarboxylic acylating agents of the present invention includedicarboxylic acylating agents such as succinic acylating agents, dimeracylating agents, and Dieis-Alder dicarboxylic acylating agents.Tricarboxylic acylating agents include trimer acylating agents andDieis-Alder tricarboxylic acylating agents.

The dimer acylating agents include products resulting from thedimerization of unsaturated fatty acids, e.g., the above-described fattyacids. Generally, the dimer acids have an average from about 18,preferably from about 28 to about 44, preferably to about 40 carbonatoms. The dimer acids have preferably about 36 carbon atoms. The dimeracids are preferably prepared from C₁₈ fatty acids, such as oleic acids.The dimer acids are described in U.S. Pat. Nos. 2,482,760, 2,482,761,2,731,481, 2,793,219, 2,964,545, 2,978,468, 3,157,681, and 3,256,304,the entire disclosures of which are incorporated herein by reference.Examples of dimer acids include Empol® 1014, 1016 and 1018 Dimer Acid,each available from Emery Industries, Inc. and Hystrene® dimer acids3675, 3680, 3687 and 3695, available from Humko Chemical.

The polycarboxylic acylating agents may be dicarboxylic acylating agentswhich are the Dieis-Alder type reaction products of an unsaturated fattyacid (e.g., the above-described fatty acids, preferably tall oil acidsand oleic acids) with alpha, beta-ethylenically unsaturated carboxylicacylating agent (e.g., acrylic or methacrylic acylating agents) such asare taught in U.S. Pat. No. 2,444,328, the disclosure of which isincorporated herein by reference. These Dieis-Alder acylating agentsinclude Westvaco® Diacid H-240, 1525 and 1550, each being commerciallyavailable from the Westvaco Corporation.

The polycarboxylic acids or anhydrides may be hydrocarbyl-substitutedsuccinic acylating agents, preferably acids or anhydrides, morepreferably anhydrides. The hydrocarbyl group generally contains anaverage from about eight, preferably from about 14, more preferably fromabout 16 to about 40, preferably to about 30, more preferably to about24, still more preferably to about 18 carbon atoms. Preferably, thehydrocarbyl group is an alkenyl group. The alkenyl group may be derivedfrom one or more of the above-described olefins.

The succinic acylating agents are prepared by reacting theabove-described olefins or isomerized olefins with unsaturatedcarboxylic acids such as fumaric acids or maleic acid or arthydride at atemperature of about 160° to about 240° C., preferably about 185° toabout 210° C. Free radical initiators (e.g., t-butyl catechol) may beused to reduce or prevent the formation of polymeric byproducts. Theprocedures for preparing the acylating agents are well known to thoseskilled in the art and have been described for example in U.S. Pat. No.3,412,111; and Ben et al, "The Ene Reaction of Maleic Anhydride WithAlkenes", J. C. S. Perkin II (1977), pages 535-537. These references areincorporated by reference for their disclosure of procedures for makingthe above acylating agents.

The polycarboxylic acylating agent may also be a tricarboxylic acylatingagent. Examples of tricarboxylic acylating agents include trimer andDieis-Alder tricarboxylic acylating agents. These acylating agentsgenerally contain an average from about 18, preferably from about 30,more preferably from about 36 to about 66, preferably to about 60 carbonatoms. Trimer acids are prepared by the trimerization of theabove-described fatty acids. The Dieis-Alder tricarboxylic acylatingagents are prepared by reacting an unsaturated monocarboxylic acid witha alpha,beta-ethylenically unsaturated dicarboxylic acid (e.g., fumaricacid or maleic acid or anhydride). The Dieis-Alder acylating agent maycontain an average from about 12, preferably from about 18 to about 40,preferably to about 30 carbon atoms. Examples of these tricarboxylicacids include Empol® 1040 available commercially from Emery Industries,Hystrene® 5460 available commercially from Humko Chemical, and Unidyme®60 available commercially from Union Camp Corporation.

The carboxylic acylating agent may be a mixture containing at least 10%by weight of a carboxylic acylating agent having at least threecarboxylic groups. The mixture preferably contains at least 50% byweight, preferably 80% by weight, preferably 90% by weight tricarboxylicacylating agent. The carboxylic acylating agents may be mixtures of theabove-identified tricarboxylic acylating agents with monocarboxylicacylating agents and the above-identified dicarboxylic acylating agents.The mixture may contain mono-, di-, or tricarboxylic acids. Themonocarboxylic acids may have from 2, preferably from about 8, morepreferably from about 12 to about 30, preferably to about 24 carbonatoms. Examples of monocarboxylic acids include acetic, propionic,butyric and fatty carboxylic acids such as oleic, stearic, linoleic,dodecanoic or tall oil acids.

Throughout this specification and in the appended claims, the term"succinic acylating agent" is intended to include carboxylic acids aswell as acid-producing derivatives thereof such as anhydrides, esters,acyl halides and mixtures thereof, unless otherwise specifically stated.The hydrocarbyl substituted succinic acylating agents may be representedby the following formulae: ##STR8## wherein R is a C₁₀ to about a C₅₀₀hydrocarbyl group. As will be set forth more fully below, when twosuccinic acylating agents are combined in a coupled molecule the R groupmay be a C₂ to about a C₅₀₀ hydrocarbyl group. Preferably, R is analiphatic or alicyclic hydrocarbyl group with less than about 10% of itscarbon-to-carbon bonds being unsaturated. As set forth more fully below,R may derived from olefin polymers. R may also be derived fromnon-polymerized olefins of from 10 to about 18 carbon atoms withalpha-olefins being particularly useful. For bridged species olefinscontaining 2 to 18 carbons may be used. Examples of such olefins includeethylene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene,1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, etc.Commercially available alpha olefin fractions such as C₁₅₋₁₈alpha-olefins, C₁₂₋₁₆ alpha-olefins, C₁₄₋₁₆ alpha-olefins, C₁₄₋₁₈alpha-olefins, C₁₆₋₁₈ alpha-olefins, etc., are particularly useful;these commercial alpha-olefin fractions also usually include minoramounts of alpha-olefins outside the given ranges. The R group may alsobe derived from olefinic compounds containing up to about 500 carbonatoms. Preferably the R group contains about 60 carbon atoms to about140 carbon atoms, and may contain polar substituents, oil-solubilizingpendant groups, and be unsaturated within the general limitationsexplained hereinabove. The production of hydrocarbyl substitutedsuccinic derivatives is well known to those skilled in the art and neednot be discussed in detail herein. Generally, these processes involvethe reaction of (1) an ethylenically unsaturated carboxylic acid, acidhalide, anhydride or ester reactant, such as maleic anhydride, with (2)an ethylenically unsaturated hydrocarbon (a chlorine free process) or achlorinated hydrocarbon (a chlorine process) at a temperature within therange of about 100°-300° C., preferably, about 100° C. to about 200° C.The product from this reaction is a hydrocarbyl-substituted succinicanhydride wherein the substituent is derived from the olefin orchlorinated hydrocarbon. The present invention works equally well withthe products produced by a chlorine process or a chlorine free process.If desired, the reaction product of the halide or olefin with theunsaturated acid may be hydrogenated to remove all or a portion of anyethylenically unsaturated covalent linkages by standard hydrogenationprocedures.

The ethylenically unsaturated hydrocarbon reactant, used in a chlorinefree process, may be derived from olefin streams. The chlorinatedhydrocarbon reactant used in a chlorine process, may be derived fromsubstantially saturated petroleum fractions or substantially saturatedolefin polymers. Polymers and chlorinated polymers derived frommono-olefins having from 2 to about 30 carbon atoms are preferred.Especially useful polymers are the polymers of 1-mono-olefins such asethylene, propene, 1-butene, isobutene, 1-hexene, 1-octene, 2-methyl-1-heptene, 3-cyclohexyl-1-butene, and 2-methyl-5-propyl-1-hexene.Polymers of medial olefins, i.e., olefins in which the olefinic linkageis not at the terminal position, likewise are useful. These areexemplified by 2-butene, 3-pentene, and 4-octene.

Interpolymers of 1-mono-olefins such as illustrated above with eachother and with other interpolymerizable olefinic substances such asaromatic olefins, cyclic olefins, and polyolefins, are also usefulsources of the ethylenically unsaturated reactant. Such interpolymersinclude for example, those prepared by polymerizing isobutene withstyrene, isobutene with butadiene, propene with isoprene, propene withisobutene, ethylene with piperylene, isobutene with chloroprene,isobutene with p-methyl-styrene, 1-hexene with 1,3-hexadiene, 1-octenewith 1-hexene, 1-heptene with 1-pentene, 3-methyl- 1-butene with1-octene, 3,3-dimethyl-1-pentene with 1-hexene, isobutene with styreneand piperylene, etc.

For reasons of hydrocarbon solubility, the interpolymers contemplatedfor use in preparing the acylating agents of this invention arepreferably substantially aliphatic and substantially saturated, that is,they should contain at least about 80% and preferably about 95%, on aweight basis, of units derived from aliphatic mono-olefins. Preferably,they will contain no more than about 5% olefinic linkages based on thetotal number of the carbon-to-carbon covalent linkages present.

The polymers and chlorinated polymers may be obtained by thepolymerization of a C₄ refinery stream having a butene content of about35% to about 75% by weight and an isobutene content of about 30% toabout 60% by weight in the presence of a Lewis acid catalyst such asaluminum chloride or boron trifluoride. These polyisobutenes preferablycontain predominantly (that is, greater than about 80% of the totalrepeat units) isobutene repeat units of the formula: ##STR9##

The polymeric materials which may be used to prepare the succinicacylating agents may be characterized, as above, by the average numberof carbon atoms which they contain. Polymeric materials are not uniform,and contain a variety of molecules of different chain lengths. Suchpolymers have also been characterized by their Mn (number averagemolecular weight). The average number of carbons correlates with the Mnof the polymer. For example, if a polymer containing an average of 100carbon atoms is reacted with maleic anhydride, the substituted succinicanhydride produced has an Mn of approximately 1500. Similarly, for apolymer containing an average of 500 carbon atoms, the substitutedsuccinic anhydride produced would have an Mn of approximately 7100. Suchpolymers have also been characterized by their Mw (weight averagemolecular weight). Because the chain lengths of a polymeric material arenot always evenly distributed, the Mw and Mn are not always identical.The polymeric materials useful in preparing the hydrocarbyl substitutedsuccinic acylating agents have Mw/Mn ratios from about 1.5 to about 4.5.Materials with ratios of about 1.5 to about 3.6 or 3.2 are useful.Materials with ratios of about 1.8, or about 2, to about 2.5, about 3.2,or about 3.6 are useful. Gel permeation chromatography may be used todetermine the values of Mw and Mn as well as the Mw/Mn ratio. A usefulmethod is disclosed in U.S. Pat. No. 4,234,435.

If an excess of maleic anhydride is reacted with the polymeric materialto form the substituted succinic acylating agent, more than one succinicgroup may add to an individual polymer chain. The amount of suchpoly-substitution may be expressed in terms of the number of succinicgroups for each equivalent weight of substituent group (derived from thepolymeric material).

The equivalent weight of the polyalkene is its Mn. The equivalents ofsubstituent groups in the succinic acylating agent is determined bydividing the total weight of substituents by the Mn of the polyalkene.The number of succinic groups per equivalent weight of substituentspresent in the succinic acylating agent may be found by comparing theequivalents of succinic groups in the molecule to the equivalents ofsubstituents. This subject is disclosed in U.S. Pat. No. 4,234,435 whichis hereby incorporated by reference for its disclosure of methodsdetermining the number of succinic groups per equivalent of substituentsand for its disclosure of methods of measuring the values of Mw and Mn.

The substituted succinic acylating agents useful in the presentinvention have from about 1.0 to about 4.5 succinic groups for eachequivalent weight of substituent group. The preferred number of succinicgroups for each equivalent weight of substituent group is from about 1.0to about 2.5 and the more preferred range is from about 1.0 to 2.0.

If acids are the desired starting material, the hydrocarbyl substitutedsuccinic anhydrides may be hydrolyzed by treatment with water or steamto the corresponding acid. Acid halides of the hydrocarbyl-substitutedsuccinic acids may be used as the acylating agents of this invention.They may be prepared by the reaction of such acids or their anhydrideswith halogenating agents such as phosphorus tribromide, phosphoruspentachloride, phosphorus oxychloride or thionyl chloride.

ALKANOL AMINES

The hydroxyamines may be primary, secondary or tertiary. The terms"hydroxyamine" "alkanol amine," and "aminoalcohol" describe the sameclass of compounds and, therefore, may be used interchangeably.

The hydroxyamines may be primary, secondary or tertiary alkanol aminesor mixtures thereof. Such amines may be represented, respectfully, bythe formulae: ##STR10## wherein each R is independently a hydrocarbylgroup of one to about eight carbon atoms or hydroxyl-substitutedhydrocarbyl group of two to about eight carbon atoms and R' is adivalent hydrocarbyl group of about two to about 18 carbon atoms. Thegroup --R'--OH in such formulae represents the hydroxyl-substitutedhydrocarbyl group. R' may be an acyclic, alicyclic or aromatic group.Typically, R' is an acyclic straight or branched alkylene group such asan ethylene, 1,2-propylene, 1,2-butylene, 1,2-octadecylene, etc. group.Where two R groups are present in the same molecule they may be joinedby a direct carbon-to-carbon bond or through a heteroatom (e.g., oxygen,nitrogen or sulfur) to form a 5-, 6-, 7- or 8-membered ring structure.Typically, however, each R is a lower alkyl group of up to seven carbonatoms.

Examples of useful N-(hydroxyl-substituted hydrocarbyl) amines includeethanolamine di-ethanolamine, ethylethanolamine, dimethylethanolamine,diethylethanolamine, di-(3-hydroxylpropyl) amine, N-(3-hydroxylbutyl)amine, N-(4-hydroxylbutyl) amine, N,N-di-(2-hydroxylpropyl) amine,N-(2-hydroxylethyl) morpholine, its thio analog, N-(2-hydroxyl ethyl)cyclohexyl amine, N-3-hydroxyl cyclopentyl amine, N-(hydroxyl ethyl)piperazine, and the like.

The tertiary alkanol amines may be reacted under condensing conditionssuch that any salts which are formed between the carboxyl groups and thetertiary amine portion of the alkanol amine molecule are converted tocondensed products such as esters. In a typical reaction, the anhydridering is opened by the alcohol to form an ester. The remaining carboxylgroup reacts with a second molecule of the alkanol amine to form ansecond ester. The tertiary alkanol amines may be reacted undernon-condensing conditions to form an ester salt product which acts as anemulsifier. The reaction is conducted under conditions such thatcondensation reactions are unlikely to occur. Under these non-condensingreaction conditions, the product of the reaction between a hydrocarbylsubstituted succinic anhydride acylating agent and a tertiary alkanolamine is an ester salt.

Further hydroxyamines are the hydroxy-substituted primary aminesdescribed in U.S. Pat. No. 3,576,743 by the general formula

    R.sub.a --NH.sub.2

wherein R_(a) is a monovalent organic group containing at least onealcoholic hydroxy group. The total number of carbon atoms in R_(a)preferably does not exceed about 20. Hydroxy-substituted aliphaticprimary amines containing a total of up to about 10 carbon atoms areuseful. The polyhydroxy-substituted alkanol primary amines wherein thereis only one amino group present (i.e., a primary amino group) having onealkyl substituent containing up to about 10 carbon atoms and up to about6 hydroxyl groups are useful. These alkanol primary amines correspond toR_(a) --NH₂ wherein R_(a) is a mono- or polyhydroxy-substituted alkylgroup. Specific examples of the hydroxy-substituted primary aminesinclude 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, p-(beta-hydroxyethyl)-aniline, 2-amino-1-propanol, 3-amino-1-propanol,2-amino-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol,N-(beta-hydroxypropyl)-N'-(beta-aminoethyl)piperazine,tris-(hydroxymethyl) amino methane (also known as trismethylolaminomethane), 2-amino-1-butanol, ethanolamine,beta-(beta-hydroxyethoxy)-ethyl amine, glucamine,4-amino-3-hydroxy-3-methyl-1-butene (which may be prepared according toprocedures known in the art by reacting isopreneoxide with ammonia),N-3-(aminopropyl)-4-(2-hydroxyethyl)-piperadine,2-amino-6-methyl-6-heptanol, 5-amino-1-pentanol,N-beta-hydroxyethyl)1,3-diamino propane, 1,3-diamino-2-hydroxypropane,N-beta-hydroxy ethoxyethyl)ethylenediamine, trismethylolaminomethane andthe like. U.S. Pat. No. 3,576,743 is incorporated herein by reference.

Hydroxyalkyl alkylene polyamines having one or more hydroxyalkylsubstituents on the nitrogen atoms, are also useful. Usefulhydroxyalkyl-substituted alkylene polyamines include those in which thehydroxyalkyl group is a lower hydroxyalkyl group, i.e., having less thaneight carbon atoms. Examples of such hydroxyalkyl-substituted polyaminesinclude N-(2-hydroxyethyl) ethylene diamine, N,N-bis(2-hydroxyethyl)ethylene diamine, 1-(2-hydroxyethyl)-piperazine,monohydroxypropyl-substituted diethylene triamine,dihydroxypropyl-substituted tetraethylene pentamine, N-(3-hydroxybutyl)tetramethylene diamine, etc. Higher homologs as are obtained bycondensation of the above-illustrated hydroxy alkylene polyaminesthrough amino groups or through hydroxy groups are likewise useful.Condensation through amino groups results in a higher amine accompaniedby removal of ammonia and condensation through the hydroxy groupsresults in products containing ether linkages accompanied by removal ofwater.

The hydroxyamines may also be ether N-(hydroxy-substitutedhydrocarbyl)amines. These are hydroxyl-substituted poly(hydrocarbyloxy)analogs of the above-described hydroxy amines (these analogs alsoinclude hydroxyl-substituted oxyalkylene analogs). SuchN-(hydroxyl-substituted hydrocarbyl) amines may be conveniently preparedby reaction of epoxides with aforedescribed-amines and may berepresented by the formulae: ##STR11## wherein x is a number of about 2to about 15, each R is independently a hydrocarbyl group of one to abouteight carbon atoms or hydroxyl-substituted hydrocarbyl group of two toabout eight carbon atoms and R' is a divalent hydrocarbyl group of abouttwo to about 18 carbon atoms.

Polyamine analogs of these hydroxy amines, particularly alkoxylatedalkylene polyamines (e.g., N,N-(diethanol)-ethylene diamine) may also beused. Such polyamines may be made by reacting alkylene amines (e.g.,ethylenediamine) with one or more alkylene oxides (e.g., ethylene oxide,octadecene oxide) of two to about 20 carbons. Similar alkyleneoxide-alkanol amine reaction products may also be used such as theproducts made by reacting the aforedescribed-described primary orsecondary alkanol amines with ethylene, propylene or higher epoxides ina 1:1 or 1:2 molar ratio. Reactant ratios and temperatures for carryingout such reactions are known to those skilled in the art.

Specific examples of alkoxylated alkylene polyamines includeN-(2-hydroxyethyl)ethylene diamine, N,N-bis(2-hydroxyethyl) ethylenediamine, 1-(2-hydroxyethyl) piperazine, mono(hydroxypropyl)-substituteddiethylene triamine, di(hydroxypropyl)-substituted tetraethylenepentamine, N-(3-hydroxybutyl)tetramethylene diamine, etc. Higherhomologs obtained by condensation of the above-illustrated hydroxyalkylene polyamines through amino groups or through hydroxy groups arelikewise useful. Condensation through amino groups results in a higheramine accompanied by removal of ammonia while condensation through thehydroxy groups results in products containing ether linkages accompaniedby removal of water. Mixtures of two or more of any of the aforesaidmono- or polyamines are also useful.

POLYALKYLENEPOLYAMINES

Alkylenepolyamines are represented by the formula: ##STR12## wherein nhas an average value from 1, or about 2 to about 10, or to about 7, orto about 5, and the "Alkylene" group has from 1, or about 2 to about 10,or to about 6, or to about 4 carbon atoms. Each R₅ is independentlyhydrogen, or an aliphatic or hydroxy-substituted aliphatic group of upto about 30 carbon atoms. R₅ may be defined the same as R₁.

Such alkylenepolyamines include methylenepolyamines, ethylenepolyamines,butylenepolyamines, propylenepolyamines, pentylenepolyamines, etc. Thehigher homologs and related heterocyclic amines such as piperazines andN-aminoalkyl-substituted piperazines are also included. Specificexamples of such polyamines are ethylenediamine, diethylenetriamine(DETA), triethylenetetraamine (TETA), tris-(2-aminoethyl)amine,propylenediamine, trimethylenediamine, tripropylenetetraamine,tetraethylenepentamine, hexaethyleneheptamine, pentaethylenehexamine,etc.

Higher homologs obtained by condensing two or more of the above-notedalkylene amines are similarly useful as are mixtures of two or more ofthe afore-described polyamines.

Ethylenepolyamines, such as those mentioned above, are useful. Suchpolyamines are described in detail under the heading Ethylene Amines inKirk Othmer's "Encyclopedia of Chemical Technology", 2d Edition, Vol. 7,pages 22-37, Interscience Publishers, New York (1965). Such polyaminesare most conveniently prepared by the reaction of ethylene dichloridewith ammonia or by reaction of an ethylene imine with a ring openingreagent such as water, ammonia, etc. These reactions result in theproduction of a complex mixture of polyalkylenepolyamines includingcyclic condensation products such as the afore-described piperazines.Ethylenepolyamine mixtures are useful.

Other useful types of polyamine mixtures are those resulting fromstripping of the above-described polyamine mixtures to leave as residuewhat is often termed "polyamine bottoms". In general, alkylenepolyaminebottoms can be characterized as having less than two, usually less than1% (by weight) material boiling below about 200 C. A typical sample ofsuch ethylene polyamine bottoms obtained from the Dow Chemical Companyof Freeport, Texas designated "E-100" has a specific gravity at 15.6 C.of 1.0168, a percent nitrogen by weight of 33.15 and a viscosity at 40C. of 121 centistokes. Gas chromatography analysis of such a samplecontains about 0.93% "Light Ends" (most probably DETA), 0.72% TETA,21.74% tetraethylene pentamine and 76.61% pentaethylenehexamine andhigher (by weight). These alkylenepolyamine bottoms include cycliccondensation products such as piperazine and higher analogs ofdiethylenetriamine, triethylenetetraamine and the like.

These alkylenepolyamine bottoms can be reacted solely with the acylatingagent or they can be used with other amines, polyamines, or mixturesthereof.

Another useful polyamine is a condensation reaction between at least onehydroxy compound with at least one polyamine reactant containing atleast one primary or secondary amino group. The hydroxy compounds arepreferably polyhydric alcohols and amines. The polyhydric alcohols aredescribed above. Preferably the hydroxy compounds are polyhydric amines.Polyhydric amines include any of the above-described monoamines reactedwith an alkylene oxide (e.g., ethylene oxide, propylene oxide, butyleneoxide, etc.) having two to about 20, or to about four carbon atoms.Examples of polyhydric amines include tri(hydroxypropyl)amine,tris-(hydroxymethyl)amino methane, 2-amino-2-methyl-1,3-propanediol,N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, andN,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine, preferablytris(hydroxymethyl)aminomethane (THAM).

Polyamines, which react with the polyhydric alcohol or amine to form thecondensation products or condensed amines, are described above.Preferred polyamine reactants include triethylenetetraamine (TETA),tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), andmixtures of polyamines such as the above-described "amine bottoms".

IMIDAZOLINES

The imidazolines useful as emulsifiers are the condensation products offatty acids and polyamines. The polyamines useful in this reaction arecharacterized by the presence of at least two primary amine groups orone primary and one secondary amine group. The polyamines used aregenerally the alkylene polyamines such as ethylene diamine,diethylenetriamine, triethylenetetraamine, etc. The fatty acids whichmay used to form this class of imidazolines include lauric, myristic,palmitic, stearic, oleic, linoleic, linolenic, eleostearic andricinoleic. Imidazolines based on fatty acids are commercially availablefrom chemical suppliers such as Croda Universal Ltd.

GLYCEROL ESTERS

Glycerol ester emulsifiers are formed by the reaction of fatty acidswith an excess of glycerol to form a mixture of mono and diglycerides.The common C-12 to C-18 fatty acids are suitable starting materials. Inplace of the fatty acid, the raw vegetable oil can be used to react withan excess of glycerol. A typical example is glycerol monooleate (Arlacel186-ICI).

POLYOXYALKYLENE ESTERS

The emulsifier may be a polyoxyalkylene fatty ester. Polyoxyalkylenefatty esters may be prepared from any polyoxyalkylene polyol or anpolyoxyalkylene alcohol and a fatty acid. The polyoxyalkylene polyol andthe polyoxyalkylene alcohol, e.g., polyoxyalkylated alcohol or phenol,are disclosed above. The fatty acid is preferably the fattymonocarboxylic acid described above. Polyoxyalkylene fatty esters areavailable commercially from Armak Company under the tradename Ethofat.Specific examples of polyoxyalkylene fatty esters include Ethofat C/15and C/25, which are coco fatty esters formed using 5 and 15 moles,respectively, of ethylene oxide; Ethofat O/15 and O/20, which are oleicesters formed using 5 and 10 moles of ethylene oxide; and Ethofat 60/15,60/20 and 60/25 which are stearic esters formed with 5, 10 and 15 molesof ethylene oxide respectively.

POLYOXYALKYLENE AMINE

Polyoxyalkylene polyamines, e.g., polyoxyalkylene diamines andpolyoxyalkylene triamines, having average molecular weights ranging fromabout 200, or about 400 up to 4000, or to about 2000 may be used asemulsifiers. Illustrative examples of these polyoxyalkylene polyaminesmay be characterized by the formulae: NH₂ -Alkylene (O-Alkylene)_(m)NH₂, wherein m has a value of about 3 to 70 and preferably about 10 to35; and R(Alkylene(O-Alkylene)_(n) NH₂)₃₋₆, wherein n is such that thetotal value is from about 1 to 40 with the proviso that the sum of allof the n's is from about 3 to about 70 and generally from about 6 toabout 35 and R is a polyvalent saturated hydrocarbon radical of up to 10carbon atoms having a valence of 3 to 6. The alkylene groups may bestraight or branched chains and contain from 1 to 7 carbon atoms andusually from 1 to 4 carbon atoms. The various alkylene groups presentmay be the same or different.

The polyoxyalkylene polyamines include the polyoxyethylene andpolyoxypropylene diamines and the polyoxypropylene triamines havingaverage molecular weights ranging from about 200 to 2000. Thepolyoxyalkylene polyamines are commercially available and may beobtained, for example, from the Huntsman Chemical Company under thetrade name "Jeffamines D-230, D-400, D-1000, D-2000, T-403, etc."

A number of hydroxyamines wherein b is zero are available from the ArmakChemical Division of Akzona, Inc., Chicago, Ill., under the generaltrade designation "Ethomeen" and "Propomeen". Specific examples of suchproducts include "Ethomeen C/15" which is an ethylene oxide condensateof a cocoamine containing about 5 moles of ethylene oxide; "EthomeenC/20" and "C/25" which also are ethylene oxide condensation productsfrom cocoamine containing about 10 and 15 moles of ethylene oxiderespectively; "Ethomeen O/12" which is an ethylene oxide condensationproduct of oleylamine containing about 2 moles of ethylene oxide permole of amine. "Ethomeen S/15" and "S/20" which are ethylene oxidecondensation products with soyaamine containing about 5 and 10 moles ofethylene oxide per mole of amine respectively; and "Ethomeen T/12, T/15"and "T/25" which are ethylene oxide condensation products of tallowaminecontaining about 2, 5 and 15 moles of ethylene oxide per mole of aminerespectively. "Propomeen O/12" is the condensation product of one moleof oleyl amine with 2 moles propylene oxide. Preferably, the salt isformed from Ethomeen C/15 or S/15 or mixtures thereof.

Commercially available examples of amines where b is 1 include"Ethoduomeen T/13", "T/20" and "T/25" which are ethylene oxidecondensation products of N-tallow trimethylene diamine containing 3, 10and 15 moles of ethylene oxide per mole of diamine, respectively.

Another group of polyoxyalkylene amines are the commercially availableliquid TETRONIC polyoxyalkylated amine polyols sold by WyandotteChemicals Corporation. These amines are represented by the generalformula: ##STR13## Such hydroxyamines are described in U.S. Pat. No.2,979,528 which is incorporated herein by reference. The hydroxyaminescorresponding to the above formula may have a number average molecularweight of up to about 10,000 wherein the ethyleneoxy groups contributeto the total number average molecular weight in the percentage rangesdiscussed above. A specific example would be such a hydroxyamine havinga number average molecular weight of about 8000 wherein the ethyleneoxygroups account for 7.5%-12% by weight of the total number averagemolecular weight. Such hydroxyamines can be prepared by reacting analkylenediamine, such as ethylenediamine, propylenediamine,hexamethylenediamine etc., with propylene oxide. Then the resultingproduct is reacted with ethylene oxide.

ETHOXYLATED ALKYLPHENOLS

The ethoxylated alkyl phenol emulsifiers are formed by the reaction ofethylene oxide with an alkyl phenol. The alkyl group can be eitherstraight chain or branched with a C8 to C12 chain length being the mostcommon. Anywhere from 1 to 40 ethylene oxide units may be include,however, for water in oil emulsions generally 1 to 8 units arepreferred. A typical example of an ethoxylated alkylphenol emulsifier isoctylphenoxy polyethoxyethanol (Triton X-15 Union Carbide).

ETHOXYLATED FATTY ALCOHOLS

The ethoxylated fatty alcohol emulsifiers are formed by the reaction ofalcohols with chain lengths of C8 to C18 with ethylene oxide. The numberof ethylene oxide units used are generally from 2 to 20.2 to 8 units arepreferred for water in oil emulsions. Either primary or secondaryalcohols can be used to form these emulsifiers. A typical example of anethoxylated fatty alcohol emulsifier is POE (2) cetylalcohol (Brij 52 -ICI Specialities Chem).

PREPARATION OF N-DODECYL-(2-HYDROXYETHYL) SULFIDE

Example I

A solution of 422.6 g of 2-mercaptoethanol and 6.4 g ofazolisisolbutyronitrile (AIBN) were prepared at ambient temperature(Solution I) 1000 g/1-dodecene were charged to a reaction vessel andheated to 80° C. under N₂ vapor space purge and 1 g of AIBN was added.Solution I was added uniformly while maintaining the reactiontemperature between 80°-88° C. After Solution I was added, 7.2 g of AIBNwere added and the reaction was maintained at 80°-88° C. until the totalacid number was less than 20. The reaction product was vacuum strippedat 20 mm Hg and 149° C. until the 1-dodecene concentration was less than4%. The reaction was cooled to 49° F. and filtered.

PREPARATION OF 2,2'-DI-(N-DODECYL-THIO)-DIETHYL ETHER

Example II

A solution of 6500.5 g of n-dodecyl-(2-hydroxyethyl) suIfide and 775 gof mixed xylenes were placed in a flask with a subsurface nitrogenpurge. The mixture was heated to a temperature of 90° C. To the mixturewas added 10 g of methanesulfonic acid. The mixture was heated to150°-160° C. and a water/xylene azeotrope was distilled. The product wasan industrial grade of 2,2'- di-(n-dodecylthio)-diethyl ether

    C.sub.12 H.sub.25 --S--CH.sub.2 CH.sub.2 --O--CH.sub.2 CH.sub.2 --S--C.sub.12 H.sub.25

COMPOSITIONS

The compositions generally contain an emulsifying amount of anemulsifier (A) a major amount of a mixture of brine and liquid oil, (B)a friction modifier of the following formula: ##STR14## where X=1 to 4,z=1 to 6,

Q=0 to 2

R₁ and R₂ are independently H or an aliphatic group containing from 1 toabout 16 carbon atoms, provided that the sum of R₁ and R₂ is between 0and about 16,

R' is an aliphatic group containing an average of from about 8 to about24 carbon atoms, and

R" is selected from the group consisting of H, an aliphatic groupcontaining between 1 and an average of about 18 carbons, and ##STR15##where Q, X, z, R₁, R₂, R' and R" are defined as set forth above, and Yis 0 to 5. In a preferred embodiment, z is 1. In the most preferredembodiment, Q=0, R₁ and R₂ are both H, X, and z all equal 1, R' isn-dodecyl, and R" is H.

The compositions may optionally include a surfactant, weighting agents,organophilic clays and lime.

The composition may contain from about 1/2 pound to about 15 pounds offriction modifier per barrel of composition. Levels of about 1 to about12 pounds or about 2 to about 10 pounds of friction modifier per barrelof composition are preferred. A level of about 4 to about 8 pounds offriction modifier per barrel of composition is most preferred. The cornposition may optionally include weighting agents, surfactantsorganophilic clays, lime, and other ingredients commonly used in welldrilling muds.

BRINE-LIQUID OIL MIXTURES

The brine is present in a mixture with a liquid oil. In one embodiment,the brine is present in the mixture in an amount from about 5, or about10, or about 15, or about 25 up to about 90, or to about 75, or to about55 parts by volume. In this embodiment, the liquid oil is present in themixture in an amount from about 10, or about 25, or about 45 up to about95, or to about 90, or to about 85, or to about 75 parts by volume. Thetotal parts by volume of brine plus the total parts by volume of liquidoil is 100 parts by volume of the mixture. In one embodiment, the brineis a discontinuous phase and the liquid oil is a continuous phase. Inanother embodiment, the mixture contains a major amount of a liquid oil,preferably from about 65, or about 70, or about 75 up to about 90, or toabout 85 parts by volume. In this embodiment, the brine is present in anamount from about 10, or about 15 up to about 35, or about 20, or about25 parts by volume of the mixture.

The brine useful in the compositions and methods of the presentinvention may be naturally occurring field brine or one formulated byvarious salts. The salts include calcium chloride, magnesium chloride,sodium chloride, potassium chloride, zinc chloride, and zinc bromide.The calcium chloride is generally present in an amount from 1% to about40% by weight of the brine. The magnesium chloride is generally presentin an amount from about 0.5% to about 24% by weight of the brine. Thesodium chloride is generally present in an amount from about 1% to about27% by weight of the brine. The potassium chloride is present in anamount from about 0.5% to about 24% by weight of the brine. The zincchloride or zinc bromide is generally present in an amount from about0.5% to about 80% by weight of the brine.

The mixture also includes a liquid oil. Examples of these oils includepetroleum oils, such as oils of lubricating viscosity, crude oils,diesel oils, mineral seal oils, kerosenes, fuel oils, white oils, andaromatic oils. Liquid oils include natural lubricating oils, such asanimal oils, vegetable oils, mineral lubricating oils, solvent or acidtreated mineral oils, oils derived from coal or shale, and syntheticoils. Vegetable oils include babassu oil, castor oil, coconut oil, cornoil, cottonseed oil, hemp oil, linseed oil, oiticica oil, olive oil,palm oil, peanut oil, rape oil, safflower, sesame oil, soybean,sunflower, and tung oil. Synthetic oils include hydrocarbon oils andhalo-substituted hydrocarbon oils such as polymerized andinterpolymerized olefins, for example polybutylenes, polypropylenes,propylene-isobutylene copolymers, chlorinated polybutylenes,poly(1-hexenes), poly(1-octenes), poly(1-decenes); alkyl benzenes, suchas dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes,di-(2-ethylhexyl)benzenes; polyphenyls such as biphenyls, terphenyls,and alkylated polyphenyls; and alkylated diphenyl ethers and alkylateddiphenyl sulfides and derivatives, analogs and homologs thereof.

Alkylene oxide polymers and interpolymers and derivatives thereof whereterminal hydroxy groups have been modified by esterification,etherification etc. constitute another class of synthetic oils. Theseare exemplified by polyoxyalkylene polymers prepared by thepolymerization of ethylene oxide or propyleneoxide, the alkyl and arylethers of these polyoxyalkylene polymers such as methylpolyisopropyleneglycol ethers, diphenyl and diethyl ethers of polyethylene glycol; andmono and polycarboxylic esters thereof, for example, the acetic esters,mixed C3-C8 fatty acid esters and C13 Oxo diester of tetraethyleneglycol. Simple aliphatic ethers may be used as synthetic oils, such as,dioctyl ether, didecyl ether, di(2-ethylhexyl) ether.

Another suitable class of synthetic oils comprises the esters of fattyacids such as ethyl oleate, lauryl hexanoate, and decyl palmitate. Theesters of dicarboxylic acids such as phthalic acid, succinic acid,maleic acid, azealic acid, sebacic acid, fumaric acid, adipic acid,linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonicacids with a variety of alcohols such as butyl alcohol, hexyl alcohol,dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethyleneglycol monoethyl ether, propylene glycol. Specific examples of theseesters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexylfumarate, dioctyl sebacate, diisoctyl azelate, dioctyl phthalate,didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester oflinoleic acid dimer, and the complex ester formed by reacting one moleof sebacic acid with two moles of tetraethylene glycol and two moles of2-ethyl-hexanoic acid.

In one embodiment, the liquid oil is a mineral or vegetable oil having akinematic viscosity from about 3, or about 3.5, or about 4 up to about15, or to about 11, or to about 10, or to about 9 centistokes at 100° C.Useful mineral oils include 40, 100, 150, 200 and 300 neutral mineraloils. Examples of specific liquid hydrocarbons include No. 2 diesel oil,Exxon ESCAID® 11 O (a petroleum distillate comprising 20% aromatics,56.6% paraffins and 23.4 naphthenes available commercially from ESSO),Total HDF 200, Conoco LVT oil (a mineral oil with the viscosity of 1.8centistokes at 40° C. available from Conoco Oil Company), and Conoco LVT200 (a mineral oil with a viscosity of 2.1 centistokes at 40° C. andless than 0.5% aromatic content, available from Conoco Oil Company).

Surfactant

The surfactant is generally present in the compositions in an amountfrom about 1, or about 2 up to about 20, or to about 15, or to about 10pounds per barrel of the composition. The function of the surfactant isto promote oil wetting of the solid particles in the drilling fluid,especially the weighting agents such as barite.

The surfactants include polyoxyalkylene amines, polyoxyalkylene amides,polyoxyalkylene alcohols, polyoxyalkylene phenols, polyoxyalkyleneesters, fatty acid salts, amine or alkaline earth or transition metalsulfonates, or reaction products of a hydroxyamine or a polyalkylenepolyamine and a carboxylic acylating agent selected from the groupconsisting of monocarboxylic acylating agents, dicarboxylic acylatingagents other than succinic acylating agents and tricarboxylic acylatingagents.

The production of sulfonic acids from detergent manufacture by-productsby reaction with, e.g., SO₃, is well known to those skilled in the art.See, for example, the article "Sulfonates" in Kirk-Othmer "Encyclopediaof Chemical Technology", Second Edition, Vol. 19, pp. 291 et seq.published by John Wiley & Sons, N.Y. (1969).

The salt of the sulfonic acid may be derived from an amine or analkaline earth or transition metal compound. Any of the above describedamines may be used. The alkaline earth and transition metal salt includemagnesium, calcium, barium, titanium, iron, and zinc salts. In oneembodiment, the metal salt is an alkaline earth metal salt, preferably acalcium or barium sulfonate, preferably a calcium sulfonate.

The metal salts are prepared by procedures known to those in the art.One method of their preparation is to mix a sulfonic acid with analkaline earth of transition metal containing base, such as an oxide orhydroxide.

Weighting Agents

The compositions of the present invention may additionally containweighting agents. These agents increase density of drilling muds andinclude galena (PbS), hematite (Fe₂ O₃), magnetite (Fe₃ O₄), ilmenite(FeTiO₃), barite (BaSO₄), siderite (FeCO₃), celestite (SrSO₄), dolomite(CaMg(CO₃) 2), and calcite (CaCO₃). Particularly useful weighting agentsinclude barium sulfate and iron oxide. Weighting agents may also besoluble salts such as sodium chloride, sodium bromide, sodium carbonate,potassium chloride, potassium carbonate, calcium bromide, zinc chloride,and zinc bromide. The weighting agents may be present in an amount fromabout 20, or about 100, or about 250, to about 900, or to about 700, orto about 600 pounds per barrel. In one embodiment, the weighting agentis present in an amount from about 300 to about 500 or about 400 poundsper barrel (ppb).

Organophilic Clay

The compositions may also contain commercial clays such as bentonite,attapulgite, sepiolite, etc. In one embodiment, the compositions mayalso include an organophilic clay. Organophilic clays are clays, such asmontmorillonite, hectorite, saponite, attapulgite and illite, that haveabsorbed amine salts. These clays are converted from water-yielding(e.g., present in the brine phase of the emulsion) to oil-yielding(e.g., present in the liquid oil phase) clays by the absorption of aminesalts. Organophilic clays are preferably oil-wettable and are dispersedin the oil phase to produce viscosity and gel properties.Montmorillonite, bentonite and attapulgite are preferred, withmontmorillonite more preferred. Water and methanol may be used toactivate the organophilic clay. The organophilic clay is present in anamount from about 1, or about 2 up to about 10, or to about 8 pounds perbarrel (ppb).

Lime

The compositions of the present invention may also include lime. Thelime in combination with the reaction products or their salts (A)provides improved thickening to the compositions. The lime is generallypresent in an amount from about 1, or about 2, up to about 10, or about8 pounds per barrel (ppb).

Well-Drilling Compositions

In one embodiment, the compositions of the present invention arewell-drilling compositions. In one embodiment, the well-drillingcompositions are invert water-in-oil emulsions. The well-drillingcompositions generally have a density of about 9, or about 10 to about21, or to about 18, or to about 14 pounds per gallon.

The following examples illustrate the compositions of the presentinvention.

EXAMPLE A-C

Composition A is prepared by combining 165 g of Conoco LVT 200 Oil, 6 gof polyamide emulsifier, 6 g of polyamide synthetic liquid blend and 5 gof lime into an appropriate size container. This mixture is then mixedfor a total of 10 minutes with moderate shear on a Hamilton Beach typemixer.

At the end of the 10 minutes mixing interval add 5 g of organophillicclay and mix for an additional 10 minutes at high shear on a HamiltonBeach type mixer.

In a suitable container add 15 g of anhydrous calcium chloride to 49 gof tap water with mixing.

To the above mixture consisting of: Conoco LVT 200 oil, polyamideemulsifier, polyamide synthetic liquid blend, lime, and organophillicclay, slowly add the warmed calcium chloride solution over 10 minuteswith stirring. Shear the entire mixture for an additional 10 minutes athigh shear on a Hamilton Beach type mixer. in this case, high shear isachieved when a deep vortex is observed.

To the previous mixture add 339 g of barite over 10 minutes with mixingat high shear on a Hamilton beach type mixer. Continue mixing at highshear for a minimum of 10 minutes or until uniform. The composition ofexample A does not contain the friction modifier and this example servesas a comparative example but is not an example of the invention.

In example B, the same procedure is followed as with A, with theinclusion of 5 g of the friction modifier of Example I added at the endof the 10 minute mixing interval. Mix thoroughly with a Hamilton Beachtype mixer until uniform.

In example C, the same procedure is followed as with A, with theinclusion of 8 g of the friction modifiers of Example I added at the endof the 10 minute mixing interval. Mix thoroughly with a Hamilton Beachtype mixer until uniform.

                  TABLE                                                           ______________________________________                                                               Example  Example                                                      Example A                                                                             B        C                                                            (all values in ppb)                                            ______________________________________                                        Conoco LVT 200   165       165      165                                       Polyamide Emulsifier                                                                           6         6        6                                         Polyamide/Synthetic Liquid                                                                     6         6        6                                         Blend                                                                         Lime (Mississippi)                                                                             5         5        5                                         Organophilic Clay                                                                              5         5        5                                         Water            49        49       49                                        Calcium Chloride (Anhydrous)                                                                   15        15       15                                        Barite           339       339      339                                       Friction Modifier of Example I                                                                 0         5        8                                         Plastic Viscosity                                                                              31        30       29                                        Yield Point      7         9        8                                         10 sec. gel      7.5       7.5      7                                         10 min. gel      8         8        7.5                                       Coefficient of Friction                                                                        0.0951    0.0496   .0455                                     % Reduction in the Coefficient                                                                           47.84    52.16                                     of Friction                                                                   ______________________________________                                    

EXAMPLE D-E

Composition D is prepared by combining 165 g of Chevron Isotec alphaolefin oil, 6 g of polyamide emulsifier, 6 g of polyamide syntheticliquid blend and 5 g of lime into an appropriate size container. Thismixture is then mixed for a total of 10 minutes with moderate shear on aHamilton Beach type mixer.

At the end of the 10 minutes mixing interval add 5 g of organophillicclay and mix for an additional 10 minutes at high shear on a HamiltonBeach type mixer.

In a suitable container add 15 g of anhydrous calcium chloride to 49 gof tap water with mixing.

To the above mixture consisting of: Chevron Isotec alpha olefin oil,polyamide emulsifier, polyamide synthetic liquid blend, lime, andorganophillic clay, slowly add the warmed calcium chloride solution over10 minutes with stirring. Shear the entire mixture for an additional 10minutes at high shear on a Hamilton Beach type mixer. in this case, highshear is achieved when a deep vortex is observed.

To the previous mixture add 339 g of Barite over 10 minutes with mixingat high shear on a Hamilton Beach type mixer. Continue mixing at highshear for a minimum of 10 minutes or until uniform. The composition ofexample D does not contain the friction modifier and this example servesas a comparative example but is not an example of the invention.

In example E, the same procedure is followed as with D, with theinclusion of 5 g of the friction modifier of Example II added at the endof the 10 minute mixing interval. Mix thoroughly with a Hamilton Beachtype mixer until uniform.

                  TABLE                                                           ______________________________________                                                          Example                                                                              Example                                                                D      E                                                                      (all values in ppb)                                         ______________________________________                                        Chevron alpha olefin oil                                                                          165      165                                              Polyamide Emulsifier                                                                              6        6                                                Polyamide/Synthetic Liquid                                                                        6        6                                                Blend                                                                         Lime (Mississippi)  5        5                                                Organophilic Clay   5        5                                                Water               49       49                                               Calcium Chloride (Anhydrous)                                                                      15       15                                               Barite              339      339                                              Friction Modifier of Example                                                                      0        5                                                II                                                                            Plastic Viscosity   26       29                                               Yield Point         6        3                                                10 sec. gel         8        8                                                10 min. gel         9        8                                                Coefficient of Friction                                                                           0.1094   0.0482                                           % Reduction in the Coefficient                                                                             55.94                                            of Friction                                                                   ______________________________________                                    

TESTING THE COEFFICIENT OF FRICTION

The coefficient of friction of the prepared drilling mud was determinedusing an OFITE Lubricity Tester. This is a standard instrument designedfor determining the coefficient of friction of drilling fluids andlubricant additives. In the standard test of drilling fluids, a hardenedsteel block and a ring are placed in contact with each other in thepresence of the fluid to be tested. A load of 150 inch pounds is placedupon a level arm which applies a pressure of between 5,000 and 10,000pounds per square inch on the fluid to be tested which is between theblock and the ring. The ring is rotated at 60 RPM. For testing of theoil-bag drilling fluids, the test was modified to increase the load to250 inch pounds mad the speed of rotation to 160 RPMs. All the testeddrilling fluids were run under these modified conditions, and,accordingly, the coefficient of friction of values are directlycomparable to each other.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the an upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

I claim:
 1. A drilling fluid composition comprising a water-in-oilemulsion formed from a brine, a liquid oil, (A) an emulsifier, (B) afriction modifier of the following formula: ##STR16## where X=1 to 4,z=1 to 6,Q=0 to 2 R₁ and R₂ are independently H or an aliphatic groupcontaining from 1 to about 16 carbon atoms, provided that the sum of thecarbon atoms in R₁ and R₂ is between 0 and about 16, R' is an aliphaticgroup containing an average of from about 8 to about 24 carbon atoms,and R" is selected from the group consisting of H, an aliphatic groupcontaining between 1 and an average of about 18 carbons, and ##STR17##where Q, X, z, R₁, R₂, R' and R" are defined as set forth above, and Yis 0 to
 5. 2. The composition of claim 1 wherein R" is hydrogen.
 3. Thecomposition of claim 1 wherein X=1.
 4. The composition of claim 1wherein R₁ is hydrogen and R₂ contains 1 to 10 carbon atoms.
 5. Thecomposition of claim 1 wherein R₂ is hydrogen and R₁ contains 1 to 10carbon atoms.
 6. The composition of claim 1 wherein R₁ is hydrogen andR₂ contains 1 to 2 carbon atoms.
 7. The composition of claim 1 whereinR₂ is hydrogen and R₁ contains 1 to 2 carbon atoms.
 8. The compositionof claim 1 wherein z is 1 to
 4. 9. The composition of claim 1 wherein zis
 1. 10. The composition of claim 2 wherein Q=0, R₁ and R₂ are bothhydrogen, X and z are both 1, and R' is n-dodecyl.
 11. The compositionof claim 1 wherein R" is an aliphatic group containing an average offrom 1 to an average of 14 carbon atoms.
 12. The composition of claim 1wherein R" is an aliphatic group containing an average of from 1 to anaverage of 12 carbon atoms.
 13. The composition of claim 1 wherein R" isan aliphatic group containing an average of from 1 to an average of 8carbon atoms.
 14. The composition of claim 1 wherein R" is an aliphaticgroup containing an average of from 1 to an average of 4 carbon atoms.15. The composition of claim 1 wherein R" is represented by thestructure: ##STR18## where X=1 to 4, R₁ and R₂ are independently H or analiphatic group containing from 1 to about 16 carbon atoms, providedthat the sum of the carbon atoms in R₁ and R₂ is between 0 and about16,R' is an aliphatic group containing an average of from about 8 toabout 24 carbon atoms, and Y is 0 to
 5. 16. The composition of claim 15wherein Y=1 to
 4. 17. The composition of claim 15 wherein Y=0 to
 2. 18.The composition of claim 15 wherein Q=0, Y=0, R₁ and R₂ are bothhydrogen, X and z are both 1, and R' is n-dodecyl.
 19. The compositionof claim 1 wherein the friction modifier is present at a level ofbetween about 1/2 and about 15 pounds of friction modifier per barrel ofcomposition.
 20. The composition of claim 1 wherein the frictionmodifier is present at a level of between about 1 to and about 12 poundsof friction modifier per barrel of composition.
 21. The composition ofclaim 1 wherein the friction modifier is present at a level of betweenabout 2 and about 10 pounds of friction modifier per barrel ofcomposition.
 22. The composition of claim 1 wherein the frictionmodifier is present at a level of between about 4 and about 8 pounds offriction modifier per barrel of composition.
 23. The composition ofclaim 1, further comprising at least one surfactant.
 24. The compositionof claim 1, further comprising at least one weighting agent.
 25. Thecomposition of claim 1, further comprising at least one at least oneorganophilic clay.
 26. The composition of claim 1, further comprisinglime.
 27. The composition of claim 1 wherein the weighting agent isbarium sulfate, iron oxide, calcium chloride, calcium bromide, zincbromide, or zinc chloride.
 28. The composition of claim 1 wherein thebrine is present in the mixture in an amount from about 5 to about 90parts by volume, and the liquid oil is present in the mixture in anamount from 10 to about 95 parts by volume, wherein the total parts byvolume of brine and hydrocarbon total 100 parts by volume.
 29. Thecomposition of claim 1 wherein the brine is a discontinuous phase andthe liquid oil is a continuous phase.
 30. A method, comprising the stepsof introducing the composition of claim 1 into a wellbore and drilling,completing or working over the wellbore hole.